Pliers for spark plug electrodes



J n- 1952 A, M. PENTLAND 2,581,439

PLIERS FOR SPARK PLUG ELECTRODES' Filed Oct. 23. 1946 INVENTOR.

ALEX. M. PENTLAND.

BY W

ATTORNEY.

Patented Jan. 8, 1952 OFFICE runes Fort SPARK PLUG ELECTRODES.

Alex Mi Pentland, United States Navy, Ann Arbor, Mich.

Application October 23, 1946, Serial No. 705,117

(Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 0. G. 757) 1 Claim.

This invention relates to new and useful improvements in a pair of pliers and more particularly to a special set of jaws for same so arranged as to fit around one of the annularly spaced electrodes of an aviation spark plug which are separated from the center electrode by a space called a spark gap.

In the operation of aircraft engines the spark plugs are changed frequently. The removed plugs are cleaned and calibrated for further use, sometimes in lots of several thousand plugs. For this work, special tools are advantageous in saving time and ensuring accuracy. A common defeet in removed spark plugs due to poor original setting or to operating temperatures is that the spark gap is too close. By using the novel pliers herein described, these spark gaps can be expeditiously enlarged to the required limits.

The principal object of the present invention is to provide a novel and new tool suitable for the adjustment of spark plug electrodes more particularly the annularly spaced electrodes which surround the centrally mounted mating electrode. These annular electrodes are so mounted that a gap can be made of the required width by the bending of the annular electrodes. This bending must be done carefully without over-stressing the metal or materials of said annular electrode or straining the center electrode and thereby causing an early failure of the spark plug in its service application.

Another object of this invention is to provide a spark plug electrode adjusting tool of the pliers type consisting of a pair of parenthesis-shaped handles, center pivot block with pin and specially shaped jaws to grip the fiat sides of the annular spaced electrodes firmly but without injury, and said pivot block being specially beveled on its under side to engage spark plug shell.

Another object of the invention is that the jaws of said pliers are so arranged that when they are clamped on the annular electrode of said spark plug and held rigidly in this position a leverage can be applied with the pliers fulcrummed on the spark plug shell so as to move the annular electrode away from its center electrode thereby increasing the width of the spark gap between the two electrodes to any desired amount.

Another object of this invention is such that both handles can be formed from any suitable material from one die or pattern, said handles being identical except for machining done after assembly.

Referring now to the drawing, Fig. 1 and Fig. 2 show a pair of pliers made in acwrdance with the present invention comprising a pair of areshaped handles I having formed integrally therewith blocks 8 and teeth 6, pivotally joined by pin 5 inserted through blocks 8. Teeth 6 mounted on the outward ends of blocks 8 are projected downwardly and coact to grip objects therebetween. Fig. 2 is an exploded isometric view of the component parts of the pliers of the present invention. A spark plug 2 shown isometrically in Fig. l discloses a center electrode 4 and its annularly spaced ground electrodes 3, the space 1 between the center electrode 4 and its annularly positioned ground electrodes 3 is a spark gap. The operation of the pliers as made according to the present invention is as follows. Teeth 6 are placed in gripping position over an annular electrode 3 and a pressure applied to the handles I so that a clamping action is applied to the sides of the annular electrodes 3 by the teeth 5. It will be noted that the tooth 6 of the lower tapered block 8 forms a curved upwardly projecting portion 6' which cooperates with the upper block to aid in stabilizing the operation of the tool during its clamping movement and when it is being used as a lever. The slight outward projection of the gripping portion of the teeth 6 facilitates the viewing of the work by the operator and provides a suitable proportion of parts for the lever operation. With the pliers tightly clamped on electrode 3 a downward pressure is applied to the handles l with the pliers fulcrummed on spark-plug shell at 9 so as to bend electrode 3 away from electrode 4 and thereby adjust the spark gap 1 to fit any specified gage (not shown). The lower block 8 is undercut as by a bevel at 10 to provide a shoulder rest on the edge of easing 2 to facilitate fulcrum action at 9.

From the foregoing description and illustration of the present invention it will be apparent that there is provided a novel type of pliers for spark plug electrode adjustments which will facilitate suchadjustments with both accuracy and safety, and which requires only one hand to operate.

While a particular embodiment of the invention has been illustrated and described herein, it is not intended that the invention be limited to such disclosure, and changes and modifications may be made and incorporated within the scope 2,581,439 3 I claim: REFERENCES CITED A pliers for increasing the spark gap of a spark The following references are of record in the plug having a spark plug shell and a bendable me of this patent: ground electrode projection therefrom, comprising: an upper and lower pivoted jaw, arms for 5 UNITED STATES PATENTS moving said jaws relative to each other, said Number Name Dat jaws including a pair of flat faced opposing 797,096 Chamberlinfi Aug. 15, 1905 blocks having outwardly and downwardly pro- 961,989 Tanner June 21, 1910 jecting teeth at their forward ends, said teeth 1,034,591 Douds Aug. 6, 1912 having opposing flat faces to grip said electrode 10 1,338,943 Sandin Apr. 27, 1920 therebetween, said block on the lower jaw hav- 1,384,209 O'Toole July 12, 1921 ing a flat tapered forward end on its bottom face 1,629,009 =Rumely May 17, 1927 to facilitate it functioning as a fulcrum, 3,558,725 Periman Jan. 11, 1949 ALEX P N LANp. 

